thompson



(No Model.) 2 Sheets-Sheet 1.

B. THOMPSON.

MULTIPLEX TELEGRAPH. V

Patented Oct. 10, 1882.

N. PETERS. Hwto-Utnngnphm Wuhingtun. D4 C.

T V I INVELNQT 1 (No Model.) 2 Sheets-Sheet 2;

B. THOMPSON.

MULTIPLE-X TELEGRAPH.

No. 265.645. Patented Oct. 10, 1882-.

ATT EST; INVENTUH:

N. PETERs mo-Lnho n mr, Wa-hin tm. u c.

UNITED STATES PATENT @rrtctav BENJAMIN THOMPSON, OF BUFFALO, NEW YORK.

MULTIPLEX TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 265,645, dated October10, 1882.

Application filed July 22, 1682. (No model.)

To all whom it may concern:

Be it known that I, BENJAMIN THOMPSON, a citizen of the United States,and a resident of Buffalo, in the county of Erie and State of New York,have invented certain new and useful Improvements in MultiplexTelegraphs, of which the following is a specification.

The object of my invention is to increase the number of messages thatmay be sent simultaneously over the same line-wire without confusion;and to this end my invention consists in combining with an ordinaryduplex, quadruplex, or other system of telegraphy in which thelinecircuit is constantly closed during the transmission of signals asystem in which the receiving apparatus is operated by induced currentsset up in the secondary of an induction-coil whose primary or inducingcoil is in the mainline circuit, and in which signals are sent byintroducing; into or withdrawing from the main-line circuit electricwaves, vibrations, or pulsations produced by any suitable means, andacting through the induction-coil upon apparatus placed in the secondarycircuit of such coil, and suitably constructed to respond to electricvibrations or waves.

My invention further consists in a novel combination upon the samecircuit of inductioncoils, each of which has a primary coil in theline-circuit and a secondary connected to suitable receiving apparatus,vibratory or wave signal transmitting apparatus and a localequating-coil combined with each inductioncoi'l apparatus and connectedthereto and to the wave-signal apparatus in such a way that vibratorycurrents setup in said local coil by the wave-signal apparatus shall actinductively to neutralize in the induction-coil circuit con taining thereceiver the effects of the vibratory currents coming from the homestation and passing through the line primary coil. By a suitablearrangement of two sets of wave-signal transmitters and induction-coilreceivers thus connected two messages may be sent in oppositedirections.

My invention consists, further, in combining such an arrangement of twosets of inductioncoils and vibratory-current transmitters with anordinary duplex or quadruplex telegraph, whereby aquadruplex or asextuplex telegraph maybe produced. In such a combination each systemmay work independently of the others, because the electric vibrations orwaves are adjusted and the ordinary duplex or quadrupleX telegraphapparatus is so constructed that said apparatus is notaffected by thevibratory currents, while, vice versa, the vibratory-curren t-receiviu gapparatus is not affected by the currents of the ordinary duplex orquadruplex transmitters, because the currents induced in thewave-sigual-receiving apparatus by the action of said transmittersaccompany only the beginning and end of a signal, are but lllO- mentary.and occur at irregular intervals.

In order that the nature of my invention may be more fully understood, 1will tirst describe the same as arranged for the purpose of sendingsignals in opposite directions by vibratory currents and as applied toan ordinary duplex telegraph, thus producing in effect aquadruplextelegraph. Its application toother systems of tel graphy will be obviousfrom the description of it as applied to a duplex telegraph.

In Figure 1 of the accompanying drawings, A and B represent two distantstations equipped so that two messages may be sentin each directionsimultaneously and without interterence.

O 0 represent the differentially-wound relays of an ordinary duplextelegraph, one of the differential-coils of each relay being in themain-line circuit L and the other in an artificial circuit, L, to earth,adjusted to equal the resistance of the main line, said coils being sowound, in the well-known way, that the current from the home station,dividing between them, will be neutralized in the home relay.

'1 1 indicate the ordinary continuity-preserving duplextelegraphtranemitters, one at each station, which are controlled by alocal electro-magnet key and battery in the ordi nary way, and each ofwhich controls a mainline battery, M B. Each is constructed so that whenat rest its insulated spring is against the book, so that the main-linebattery M B- is cut out, and the circuit to earth is through aresistance, R, adjusted to equal the section of battery M B, while whenthe key is operatcd the connection through thehook is broken and thespring is in contact with a stop, so as to introduce the main battery MB into the main-line circuit, the operation of the key T being,however,always unattended with any rupture of the general circuit. In thepresent instance the circuit includes a second section of main battery,M B, the function of which is to produce the vibratory currents; but theefi'ect of this is only to render it necessary to adjust the retractorsof the relays O 0 above the tension of sections M B,so that whenever thelatter are allowed to flow uninterruptedly the relays O 0 shall not beaffected. I

S S are the sounders forthe ielays G U. These sounders are controlledand operated in the ordinary way by the relay-contacts and a localbattery. teries M B at the opposite ends of line is such that theywillre-enforce one another. The operation of this class of duplextelegraphs, being well understood, need not be described in detail.

I I indicate the induction-coils of the vibratory or wave signal system,each of which is wound with three independent coils, which are placedeither beside or over one another in any suitable manner, and which Ishall term, for the sakeof distinction,the line primary, the local orequating primary,and the receiver secondary coils. V

F indicates the line primary, which is of the usual resistance, and isdirectly in the line-circuit.

E indicates the receiver secondary coil, Which is of any desiredresistance, but is preferably a quantity or low-resistance coil, andwhich is included in circuit with a receiver electro-magnet, H,properlywound to be operated by means of the currents induced in thecoil E by the coil F and by the equating-coil G, to be presentlydescribed. The armatures ot' the receivers H are suitably constructed oradjusted in a well-known manner to vibrate by the action of vibratory orpulsatory currents induced in the receiver-secondary E by thevibratorycurrents flowing on the main line, and (ach plays between twoelectrically-connected contact-points, as shown, firmly adjusted, sothat the movements of the armature shall be as small as possible inpassing from one to the other, but shall be sufficiently large to breakfor an instant the local circuit containing the sounder M, so that whenthe armature is rapidly vibrating there shall be practically a break ofthe local circuit, and thesounder Will be demagnetized, but when saidarmature is against either its front or its back stop the local circuitshall be closed. The armatures of H H at both stations are soconstructed and adj ust ed that they will vibrate with currents orpulsations of the same rapidity.

l isasecond induction-coil, the core ofwhich servesin the presentinstance as the attractingcore of an automatic electromagnetic vibrator.

K indicates the armature of the automatic vibrator, the circuit throughwhose back stop The arrangement of the bat-- includes the primary orquantity coil N of the. induction-coil l, a wire, 8, leading to a pointbetween the two sections of main battery and a wire, 9, leading to earththrough the spring and hook of a key, T, when said keyis at rest andagainst its back stop. As will be readily seen, the action of thevibrator K is to alternately break and close a short circuit for thesection of battery M B to earth, thus alternately allowing the same toflow to line and withdrawing it from line, so as to produce vibratorycurrents or pulsations 011 the main line. Key T is operated in theordinary way by a' local electro-magnet battery and key. Theinduction-coil l induces the local equating-currents which flow throughthe local equating-coilGot'inductioncoil Iat same station, and serve toneutralize the effects of the main-line pulsations or vibrations flowingthrough coil F and produced by the vibrator K at'same station, whichcurrents would otherwise produce in the secondary E currents orvibrations that would disturb the proper operation of the apparatus. Theneutralization is effected by thelocal equating-coil G on I, which coilis an intensity-coil and is in circuit with the secondary coil P on I,which latter is also an intensity-coil and is properly connected withcoil Gr, so that the currents generated in P by the makes and breaks ofthe current flowing through the primary N and the vibrator K shall flowin the coil G and tend to produce simultaneously in thereceiver-secondary E currents the reverse of those which would beproduced by the line pulsations or waves from battery M B at samestation consequent upon the make and break of the battery sh'ortcircuitthrough the vibrator and induction coil 1. Vibrators K at both stationsare adjusted or constructed to operate at the same rate of speed, andwhen operating each keeps in vibration the receiver H at the oppositeend of the line, the effect of the pulsations or vibrations upon thereceiver H at the same station being neutralized in the manner justdescribed, so that if the vibrator at one end of the line stop actingthe receiver at the distant end will cease to operate, although thevibrator at the same station with it may be working.

The general operation is as follows: The transmitters T at both stationsbeing at rest, sections M B are cut out and the line-circuit is directlyto the section M B. Transmitter T being also at rest, the circuitsthrough the electro-magnetic vibrator are closed, and said vibratorsboth operate to alternately short-circuit and break the short circuit ofsection M B, thus producin'ginthemain-line circuit rapid pulsations orvibrations. The pulsations or vibrations produced at station A, forinstance, keep the Vibratory receiver H at station 13 inconstantoperation by means of the currents induced from coil F at thatstation into coil E but such pulsations have no effect at station A,because of the counteracting or neutralizingintluence of the vibrationssimultaneously produced in the equatingprimary G at that station. In asimilar way the vibratorK at station B keeps the vibrating receiver H atstation A in constant operation so long as the transmitter T at B isclosed, but produces no effect upon the receiver H at B. for the samereasonjust stated with reference to vibrator K at station A. Thevibratory receivers H being thus kept in constant operation, theirarmatures play between the contact-stops, and the circuit throughsounder M is practically open. The relays O are not charged sufficientlyto overcome the tension of their retractors, so that sounders S are notaffected by the vibratory or wavecurrents. 1f now the transmitter T atstation A, for instance, be operated, thus breaking the circuit throughthe vibrator and ind notion-coil I, the vibratoryor wave currentsproduced at A will be cut off, and section M B ofbattery will flowuninterruptedlytoline. Vibrator-receiverHatthedistant end of line willtherefore cease to operate, and it's annatnre-lcver will remain at restagainst its back stop, thus closing the circuit ofsounder M.Viln'ator-receiver at home station A will continue to operate by theaction of the vibrator at station B, and the circuitof its sounder Mwill remain open. The relay 0 at station B is not affected by section MB of battery, its retraetor being adjusted above the effects of suchbattery. If both transmitters T be operated together, the vibratingcurrents produced at both stations will cease to flow, and the receiversH coming to rest both sonnders M will be operated. Neither of the relaysG will be aifected, for the reason already stated. If while eitherviln'ator-receiver H at either station is at rest, owing to theoperation of transmitter T at the other station, a transmitter T ateither station be operated so as to throw section M B of battery toline, the sounder M of such receiver will not be disturbed, as theinduced current produced in H merely carries the armature-lever from itsback to its front contact so quickly that sounder M does not havetimetodischarge and open. The receiver (3 is operated by section M B ofbattery after the usual manner of aduplex receiving-instrument, theretractor being properly adjusted for current from section M B, and thesounder S is thus caused to respond. It is of course to be understoodthat section M B of battery 'is sufficient to operate the relay 0whether section M B be on or off the line.

It is obviously within the scope of the invention to operate thevibrator K-by other means instead of by the induction-coil I, and forthis purpose a separate operating electro-magnetor other device such asis well known in the art might be used. So, too, it would be entirelywithin the scope of my invention to produce the vibratory currents byother means instead of by throwing the main-line battery into waves orvibrations. A triplex might beformed by the arrangement described bydispensing with the secondary circuit containing secondary coil P andequating-primary G. In this case, as before, the duplex could be workedby the difl'erential relays, while the vibrators andinduction apparatusI could be used for single transmission.

I do not desire to limit myself to the combination herein shown anddescribed, as there are many forms of duplex apparatus to which myvibratory or wave combination may be connected in order thata duplex maybe formed into a triplex or quadruplex; or a quadruplex combinedtherewith may be formed in to a quintuplex orsextuplex. In any case itis only necessary, in order to combine the above arrangement for sendingsignals by vibratory current with other systems of transmission, thatsaid system should employ transmitting apparatus constructed in such away that a continuity of the general circuit will be preserved, and apath thus always provided for the vibratory signals. Signals sent bysuch other s stem would in no case affect the vibratory arrangementdescribed, for the reasons already stated.

I will now proceed to show and describe a modified form of the vibratoryor wave combination that may be used to form a triplex that is, Bostonand New York may work duplex while New York and Hartford are workingsingle on the same wire, or while Boston and Hartford are workingsingle; or any number of intermediate oflices may be placed upon theduplex wire; so that the intermediate stations may work with each otheror with the terminals or the terminals with each other. Thus a duplexmay be operated between any two points, while simultaneously asingle-message system, formingan effective Morse circuit, may be woikedon the same wire.

In Fig. 2, A B G D are four stations on a single wire. A and D are theterminals. B and O are the intermediates. A and D work duplex by awell-known method, which is a polarized duplex, the static charge anddischarge of theline beingeliininatcd by any suitable device. B and Gare arranged to work single by a modified form of the inductionarrangement shown in Fig. 1. At station B,K is a four-pointed key,thefront and back points being insulated from each other; LB, a localbattery; V, an electromagnetic vibrator wound forquantity; H,aninductionapparatus wound with three coils of wile whose line-coil is ofthe ordinary resistance required in Morse relays, or about three hundredand fifty ohms. The other two coils are wound for quantity; S, theelcctro-magnet of a vibrator-receiver wound for quantity whose localpoints are arranged to complete the local circuit of L B either throughfront or back contact-points.

M is a local electro-magnet wound with two coils of wire, each coil forquantity and of the same sized wire. Thus when S is unexcited theefi'ect of L, B on M is neutralized, as the current divide-s equally butoppositely through the two coils of M. As described in the op- IIOeration of vibratory or wave currents in Fig. 1, nothing but vibratoryor wave currents will actuate the armature of electro-magnet S.

It will not be necessary to explain parts at station as they are thesame as shown at B,and anynuniberofstations may be arranged asintermediates or terminals on the same vibratory or wave plan. Referringto station B, when operator closes key K battery L B 0perates thevibrator V, which is placed in circuit with the lower coil of inductionapparatus 111, thus inducing in the. line-coil F vibrations orpulsations which pass over the line to station O, and, circulating initsline-coils F, in-

duce in the local secondary E currents which pass through the barkcontact of key K and receiver S at that station, and, by putting itslever into vibration, disturb the balance between the coils on sounder Mand allow the current from B passing through the lower coil of saidsounder to actuate the same. As will be readily setn, when the key K isoperated at station E the circuit of the coil E and instrument S isbroken, so that all of the inducing action of the coil connected to thevibrator is expended in producing currents in theline-coil. Were thiscircuitnot broken, the induced currents would be absorbed by the loresistance coil containing the instrument S, and thus be prevented fromforming in the linecoil and passing to line. The operation of thetransmitters at the stations A and I) does not interfere with the properaction of the a pparatus at B or 0, since the receivers at the latterstations are not in the line-circuit and are only operated by vibratorycurrents, as before explained in connection with Fig. 1. It is obviousthat this arrangement is applicable to many forms of duplex to form atriplex, and also to many forms oi'quadruplex to form a quintuplex, andalso to work intermediates on a quadruplex line during the operation ofthe quadrnplex.

Fig. 3 shows a modified form of the receiving arrangement shown inFig. 1. I indicates the induction apparatus described in Fig. 1; S anelectro-niagnet wound for quantity, with its local points on the backcontact; S an ordinary sounder; S an electromagnet whose function is tocompensate for or neutralize the disturbing action of ordinary currentssent by the duplex or other apparatus and circulating through theline-coil ofindnction apparatus I, which may momentarily excite S enoughto separate thelocal points. Atthe moment, however, that the pointsseparate the dischargemain unattracted until such time as the armatureof S comes to rest.

It is obvious that the receiving arrangement shown in Fig. 3 is onlyapplicable to the arrangement in which vibratory or wave currents aresent into line while the key is at rest, the closing of the key actingto shut off the vibrations or waves, so that the retractor of S canconnect the local points, and thereby close the circuit of sounder S Itis evident that electro-magnet S connected as shown in Fig. 3, is asuitable arrangement to obviate the static difiiculties caused by thecharging and discharging of the main line in multiplex telegraphs.

It will be understood that the secondary circuit of the vibrator K,(shown in Fig. 1,) which serves as an equating device for the outgoingvibratory or wave currents, might be dispensed with and the ordinaryequating-circuit to earth be extended so as to include an equating-coilupon the induction-coil I, so that the outgoing waves or pulsationsproduced by the vibrator would produce no effect on thewave-signal-receiving apparatus at the same station. Other equatingdevices might be employed without departing from the spirit of myinvention. My invention is not limited to any particular method ofproducing the vibratory or wavecurrents, the gist of the inventionconsisting in the arrangement of the wave-current receivers in the thesecondary circuit of an induction-coil whose primary is in theline-circuit, so that ordinary signals by an ordinary duplex orquadruplex telegraph or similar system of telegraphy in which there is a(wnstantly-closed circuit may be sentover the same wire simultaneouslywith the vibratory-current signals without disturb ing the receivers forthe latter.

NVhat 1 claim as my invention is 1. The com bination, upon the sametelegraphline, of continuity-preserving transmitters interposed in the.main line, and Wave or vibratory signal apparatus the receivers of whichare placed in the local secondary circuit of an induction-coil whoseprimary is in the mainline circuit, substantially as and for the purposedescribed.

2. The combination, u pon the sametelegraphline, of a Morse transmitterinterposed in the main line and provided with continuity-preservingpoints, suitable receiving apparatus therefor, an induction-coil whoseprimary forms a portion of the main line, a vibratory receiver in thesecondary of said coil, and devices for producing in the main linevibratory currents, said devices being in a circuit independent of thesecondary of said coil and controlled by a suitable transmitting-key.

3. The combination, with a main telegraphline used for signaling byapparatus Working wi hout rupture of the main-line circuit, of vibratoryor wave signal receiving apparatus whose electro-magnet is included inthe local secondary circuit of an induction-coil, the primary coil ofwhich latter is included in the IIO main-line circuit, alooal batterycontrolled by the vibrating armature of the receiver, and anelectro-magne't or sounder in the local-battery circuit.

4. The combination, with the main line ofa duplex telegraph, asdescribed, of an induction-coil the primary of which is in the mainlinecircuit, an eleotromaguet having a vibratory armature connected in thelocal secondary circuit of said induction-coil, back and frontcontact-stops for the armature or other vibrating part of theelectro-magnet, and a local batteryand electro-magnet whose circuitisthrough said stops.

5. The combination of main line L, induction-coil I, coils E F,electro-magnet H, and armature therefor, local battery connected to thearmature-lever and to a receiving elect-romagnet, and back and .frontcontact-stops for the armature electrically connected to one another.

6. The com binatiou, upon the same main line of duplex or quadruplextelegraph apparatus, of an automatic vibrator in a short circuit for asection of the main-line battery, an induction-coil in the mainlinecircuit, and a vibratory receiving apparatus in a local secondarycircuit of said induction-coil.

7. The combination, upon the same telegraph-line, ot'duplex telegraphapparatus at each end thereof, controlling a section, M B, of amain-line battery, automatic vibrators in a short circuit for thesection M B of battery at each end and operating at the same rate ofspeed, and vibratory-current-receiving apparatus at each end of the lineconnected to the local secondarycircuit of a' line induction-coil.

8. The combination, substantially as described, of main batteries M B, MB at both ends of a telegraph -line, duplex telegraphtransmitterscontrolling one section of said batteries, an automatic vibratorcontrolling the other section, and induction-coils I at each endprovided each with a local-receiver secondary,

a line primary, and a local equating primary coil.

9. The combination, with an induction-coil having a local-receiversecondary, a line primary, and a local equating primary coil, of anautomatic vibrator and a second inductioncoil Whose primary is incircuit with the vibrator, and whose secondary is connected to theequating-primary of the first-named coil.

10. The combination, with a line primary coil, of a receiver secondarylocal coil, an electro-maguet in circuit with the latter, a vibratoryarmature, and front and back stops for the latter electrically connectedand in circuit with a local battery.

11. The combination of duplex transmitters T, normally disconnected fromsections M B of battery, transmitters T, norm ally connected with thecontacts of an automatic vibrator in a short circuit for section M B ofbattery, suitable duplex telegraph-receivers, O, and vibratoryreceiver-magnets in the local secondary circuits of induction -coilswhose primaries form portions of the, main-line circuit.

12. The combination of induction -coil I, wound and connected asdescribed, inductioncoil 1, and automatic vibrator K, actuated therebyand in circuit with the primary of said coil, as and for the purposedescribed.

13. The combination, substantially as described, of avibratorycurrentreceiver, a local circuit controlled thereby andcontaining a receiving electro-magnet, and an clectromagnet placed in aderived circuit to the receiver electro-magnet, so as to prevent by itsdischarge a false signal by the momentary action of armature for thevibratory-current receiver.

Signed at Buffalo, in the county of Erie and State of New York,this 11thday of July, A. D. 1882.

BENJAMIN THOMPSON.

Witnesses 7 JAMES SANGSTER, OLIVER S. BRUon.

